Geochronology of an Apollo 16 Clast Provides Evidence for a Basin-Forming Impact 4.3 Billion Years Ago.

We examined lithic breccias from the Apollo sample collection in order to identify ferroan anorthosite samples suitable for geochronology, and better define the age relationships between rocks of the lunar highlands. Clast 3A is a previously unstudied noritic anorthosite from Apollo 16 lithic breccia 60016 with textural evidence of slow subsolidus recrystallization. We estimate a cooling rate of ~10 °C/Myr and calculate a pyroxene solvus temperature of 1,100-1,000 °C. Pyroxene exsolution lamellae (1-3 µm) indicate that the last stage of cooling was rapid at ~0.2 °C/year, typical of rates observed in thick ejecta blankets. We calculate concordant ages from the 147Sm-143Nd, 146Sm-142Nd, Rb-Sr, and Ar-Ar isotopic systems of 4,302 ± 28, 4,296 + 39/-53, 4,275 ± 38, and 4,311 ± 31 Ma, respectively, with a weighted average of 4,304 ± 12 Ma. The closure temperature of the Sm-Nd system is ~855 ± 14 °C, whereas the closure temperature of the Ar-Ar system is 275 ± 25 °C. Cooling from 855 to 275 °C at 10 °C/Myr should result in an age difference between the two isotopic systems of ~60 Myr. The concordant Sm-Nd, Rb-Sr, and Ar-Ar ages imply that they record the time the rock was excavated by a large impact from the midcrust. The ages clearly predate various late accretion scenarios in which an uptick in impacts at 3.8 Ga is preceded by a period of relative quiescence between 4.4 and ~4.1 Ga, and instead are consistent with decreasing accretion rates following the formation of the Moon.

Variable nutrient stoichiometry (carbon:nitrogen:phosphorus) across trophic levels determines community and ecosystem properties in an oligotrophic mangrove system.

Our study investigated the carbon:nitrogen:phosphorus (C:N:P) stoichiometry of mangrove island of the Mesoamerican Barrier Reef (Twin Cays, Belize). The C:N:P of abiotic and biotic components of this oligotrophic ecosystem was measured and served to build networks of nutrient flows for three distinct mangrove forest zones (tall seaward fringing forest, inland dwarf forests and a transitional zone). Between forest zones, the stoichiometry of primary producers, heterotrophs and abiotic components did not change significantly, but there was a significant difference in C:N:P, and C, N, and P biomass, between the functional groups mangrove trees, other primary producers, heterotrophs, and abiotic components. C:N:P decreased with increasing trophic level. Nutrient recycling in the food webs was highest for P, and high transfer efficiencies between trophic levels of P and N also indicated an overall shortage of these nutrients when compared to C. Heterotrophs were sometimes, but not always, limited by the same nutrient as the primary producers. Mangrove trees and the primary tree consumers were P limited, whereas the invertebrates consuming leaf litter and detritus were N limited. Most compartments were limited by P or N (not by C), and the relative depletion rate of food sources was fastest for P. P transfers thus constituted a bottleneck of nutrient transfer on Twin Cays. This is the first comprehensive ecosystem study of nutrient transfers in a mangrove ecosystem, illustrating some mechanisms (e.g. recycling rates, transfer efficiencies) which oligotrophic systems use in order to build up biomass and food webs spanning various trophic levels.

Non-destructive functionalisation for atomic layer deposition of metal oxides on carbon nanotubes: effect of linking agents and defects.

The hybridisation of metal oxides and nanocarbons has created a promising new class of functional materials for environmental and sustainable energy applications. The performance of such hybrids can be further improved by rationally designing interfaces and morphologies. Atomic layer deposition (ALD) is among the most powerful techniques for the controlled deposition of inorganic compounds, due to its ability to form conformal coatings on porous substrates at low temperatures with high surface sensitivity and atomic control of film thickness. The hydrophobic nature of the nanocarbon surface has so far limited the applicability of ALD on CNTs. Herein we investigate the role of structural defects in CNTs, both intrinsic and induced by acid treatment, on coverage, uniformity and crystallinity of ZnO coatings. Furthermore, we demonstrate the potential of small aromatic molecules, including benzyl alcohol (BA), naphthalene carboxylic acid (NA) and pyrene carboxylic acid (PCA), as active nucleation sites and linking agents. Importantly, only PCA exhibits sufficiently strong interactions with the pristine CNT surface to withstand desorption under reaction conditions. Thus, PCA enables a versatile and non-destructive alternative route for the deposition of highly uniform metal oxide coatings onto pristine CNTs via ALD over a wide temperature range and without the typical surface corrosion induced by covalent functionalisation. Importantly, preliminary tests demonstrated that the improved morphology obtained with PCA has indeed considerably increased the hybrid's photocatalytic activity towards hydrogen evolution via sacrificial water splitting. The concept demonstrated in this work is transferable to a wide range of other inorganic compounds including metal oxides, metal (oxy)nitrides and metal chalcogenides on a variety of nanocarbons.

The chlorine isotope composition of the moon and implications for an anhydrous mantle.

Arguably, the most striking geochemical distinction between Earth and the Moon has been the virtual lack of water (hydrogen) in the latter. This conclusion was recently challenged on the basis of geochemical data from lunar materials that suggest that the Moon's water content might be far higher than previously believed. We measured the chlorine isotope composition of Apollo basalts and glasses and found that the range of isotopic values [from -1 to +24 per mil (per thousand) versus standard mean ocean chloride] is 25 times the range for Earth. The huge isotopic spread is explained by volatilization of metal halides during basalt eruption--a process that could only occur if the Moon had hydrogen concentrations lower than those of Earth by a factor of approximately 10(4) to 10(5), implying that the lunar interior is essentially anhydrous.

A class-wide phylogenetic assessment of Dothideomycetes.

We present a comprehensive phylogeny derived from 5 genes, nucSSU, nucLSU rDNA, TEF1, RPB1 and RPB2, for 356 isolates and 41 families (six newly described in this volume) in Dothideomycetes. All currently accepted orders in the class are represented for the first time in addition to numerous previously unplaced lineages. Subclass Pleosporomycetidae is expanded to include the aquatic order Jahnulales. An ancestral reconstruction of basic nutritional modes supports numerous transitions from saprobic life histories to plant associated and lichenised modes and a transition from terrestrial to aquatic habitats are confirmed. Finally, a genomic comparison of 6 dothideomycete genomes with other fungi finds a high level of unique protein associated with the class, supporting its delineation as a separate taxon.

The molecular phylogeny of freshwater Dothideomycetes.

The freshwater Dothideomycetes species are an ecological rather than taxonomic group and comprise approximately 178 meiosporic and mitosporic species. Due to convergent or parallel morphological adaptations to aquatic habitats, it is difficult to determine phylogenetic relationships among freshwater taxa and among freshwater, marine and terrestrial taxa based solely on morphology. We conducted molecular sequence-based phylogenetic analyses using nuclear ribosomal sequences (SSU and/or LSU) for 84 isolates of described and undescribed freshwater Dothideomycetes and 85 additional taxa representative of the major orders and families of Dothideomycetes. Results indicated that this ecological group is not monophyletic and all the freshwater taxa, except three aeroaquatic Tubeufiaceae, occur in Pleosporomycetidae as opposed to Dothideomycetidae. Four clades comprised of only freshwater taxa were recovered. The largest of these is the Jahnulales clade consisting of 13 species, two of which are the anamorphs Brachiosphaera tropicalis and Xylomyces chlamydosporus. The second most speciose clade is the Lindgomycetaceae clade consisting of nine taxa including the anamorph Taeniolella typhoides. The Lindgomycetaceae clade consists of taxa formerly described in Massarina, Lophiostoma, and Massariosphaeriae.g.,Massarina ingoldiana, Lophiostoma breviappendiculatum, and Massariosphaeria typhicola and several newly described and undescribed taxa. The aquatic family Amniculicolaceae, including three species of Amniculicola, Semimassariosphaeria typhicola and the anamorph, Anguillospora longissima, was well supported. A fourth clade of freshwater species consisting of Tingoldiago graminicola,Lentithecium aquaticum,L. arundinaceum and undescribed taxon A-369-2b was not well supported with maximum likelihood bootstrap and Bayesian posterior probability. Eight freshwater taxa occurred along with terrestrial species in the Lophiostoma clades 1 and 2. Two taxa lacking statistical support for their placement with any taxa included in this study are considered singletons within Pleosporomycetidae. These singletons, Ocala scalariformis, and Lepidopterella palustris, are morphologically distinct from other taxa in Pleosporomycetidae. This study suggests that freshwater Dothideomycetes are related to terrestrial taxa and have adapted to freshwater habitats numerous times. In some cases (Jahnulales and Lindgomycetaceae), species radiation appears to have occurred. Additional collections and molecular study are required to further clarify the phylogeny of this interesting ecological group.

Laser heating of solid matter by light-pressure-driven shocks at ultrarelativistic intensities.

The heating of solid targets irradiated by 5 x 10(20) W cm(-2), 0.8 ps, 1.05 microm wavelength laser light is studied by x-ray spectroscopy of the K-shell emission from thin layers of Ni, Mo, and V. A surface layer is heated to approximately 5 keV with an axial temperature gradient of 0.6 microm scale length. Images of Ni Ly(alpha) show the hot region has 100 G bar light pressure compresses the preformed plasma and drives a shock into the solid, heating a thin layer.

Freshwater ascomycetes: Aquapoterium pinicola, a new genus and species of Helotiales (leotiomycetes) from Florida.

As part of a survey of freshwater ascomycetes in Florida an unusual discomycete fungus belonging in the Helotiales was found on submerged Pinus needles. This fungus is described and illustrated as a new genus and species, Aquapoterium pinicola, based on morphological data. Aquapoterium pinicola is characterized by minute, hyaline apothecia with an excipulum one cell layer thick of parallel hyphae composed of chains of cells narrow at the basal end and enlarged at the apical end and aseptate ascospores that are surrounded by a gelatinous sheath. Analyses of the nuclear ribosomal large subunit DNA sequence data confirmed its placement within the Helotiales but failed to resolve its familial placement.

Rhodococcus equi lung infection in an allogeneic hematopoietic stem cell transplant recipient.

In this report, we describe a case of Rhodococcus equi lung infection diagnosed in an allogeneic hematopoietic stem cell transplant with oral graft-versus-host disease 3 months after stem cell infusion. The lung lesion persisted despite an approximate 3 months of vancomycin therapy, but then responded favorably to a combination of intravenous ertapenem at 1 g daily and oral rifampin at 600 mg daily for 1 month. An overview of Rhodococcus infection in transplant recipients is presented. This case and the discussed literature suggest that combination antibiotic therapy is warranted in patients with decreased humoral and cellular immunity.

Skills acquired on virtual reality laparoscopic simulators transfer into the operating room in a blinded, randomised, controlled trial.

Virtual reality surgical simulators have proven value in the acquisition and assessment of laparoscopic skills. In this study, we investigated skill transfer from a virtual reality laparoscopic simulator into the operating room, using a blinded, randomised, controlled trial design. Surgical trainees using the LapSim System performed significantly better at their first real-world attempt at a laparoscopic task than their colleagues who had not received similar training, as measured independently by a number of expert surgical observers using four criteria.

Jahnula species from North and Central America, including three new species.

Three new species of loculoascomycetes collected from freshwater habitats in North America are described as new species of Jahnula (Jahnulales, Dothideomycetes). All three share these morphological features: hyaline to blackish translucent, membranous ascomata with subtending, wide, septate brown, spreading hyphae; peridia composed of large angular cells; hamathecium of septate pseudoparaphyses; 8-spored, clavate to cylindrical asci; and 1-septate, broadly fusiform, brown, multiguttulate ascospores. Four additional species, J. aquatica, J. bipolaris, J. potamophila, and J. seychellensis, are reported for the first time from the western hemisphere.

An elevated C-reactive protein concentration, prior to surgery, predicts poor cancer-specific survival in patients undergoing resection for gastro-oesophageal cancer.

There is increasing evidence that the presence of an ongoing systemic inflammatory response is associated with poor outcome in patients undergoing resection for a variety of tumours. The aim of the present study was to examine the relationship between clinico-pathological status, preoperative C-reactive protein concentration and cancer-specific survival in patients undergoing resection for gastro-oesophageal cancer. One hundred and twenty patients attending the upper gastrointestinal surgical unit in the Royal Infirmary, Glasgow, who were selected for potentially curative surgery, were included in the study. Laboratory measurements of haemoglobin, white cell, lymphocyte and platelet counts, albumin and C-reactive protein were carried out at the time of diagnosis. All patients underwent en-bloc resection with lymphadenectomy and survived at least 30 days following surgery. On multivariate analysis, only the positive to total lymph node ratio (hazard ratio (HR) 2.02, 95% confidence interval (CI) 1.44-2.84, P<0.001) and preoperative C-reactive protein concentration (HR 3.53, 95% CI 1.88-6.64, P<0.001) were independent predictors of cancer-specific survival. The patient group with no evidence of a preoperative systemic inflammatory response (C-reactive protein < or =10 mg l(-1)) had a median survival of 79 months compared with 19 months in the elevated systemic inflammatory response group (P<0.001). The results of the present study indicate that in patients selected to undergo potentially curative resection for gastro-oesophageal cancer, the presence of an elevated preoperative C-reactive protein concentration is an independent predictor of poor cancer-specific survival.

Cytokeratin 7 and 20 expression in intestinal metaplasia of the distal oesophagus: relationship to gastro-oesophageal reflux disease.

AIMS: Intestinal metaplasia and gastro-oesophageal reflux disease typify classical Barrett's oesophagus. Cytokeratin (CK) 7 and 20 phenotypes differentiate intestinal metaplasia in long segment Barrett's oesophagus from gastric intestinal metaplasia. This study examines the relationship between CK7/20 phenotypes and reflux disease in intestinal metaplasia of the distal oesophagus. METHODS AND RESULTS: Eighty patients with oesophageal pH studies included 30 with long segment Barrett's, 16 with short segment Barrett's and 34 with intestinal meatplasia of the gastro-oesophageal junction. Representative biopsy specimens were immunostained for CK7 and CK20. All 30 long segment patients demonstrated a Barrett's CK7/20 phenotype. All nine short segment patients with gastro-oesophageal reflux had a Barrett's CK7/20 phenotype, while four of seven short segment patients without reflux had a gastric CK7/20 phenotype (P = 0.019). Of 14 patients with intestinal metaplasia of the gastro-oesophageal junction and reflux, 10 (71%) had a Barrett's CK7/20 phenotype, compared with 11 (55%) of the 20 non-reflux patients. CONCLUSIONS: CK7/20 immunoreactivity for patients with intestinal metaplasia of the distal oesophagus without long segment Barrett's oesophagus suggests a heterogeneous group, with an association between Barrett's CK7/20 pattern and gastro-oesophageal reflux disease in both short segment Barrett's and intestinal metaplasia of the gastro-oesophageal junction.

A reassessment of two freshwater ascomycetes, Ceriospora caudae-suis and Submersisphaeria aquatica.

Ceriospora caudae-suis and Submersisphaeria aquatica, two freshwater pyrenomycetes reported infrequently since their original description, occur commonly on submerged woody debris in the USA. Based on analyses of 28S rDNA sequence data and morphology, both species belong in the Annulatascaceae. Ceriospora caudae-suis is transferred to Pseudoproboscispora, a genus in the Annulatascaceae with similar overall morphology and ecology. Submersisphaeria aquatica is redescribed and illustrated based on additional collections.

Systematics of Halosarpheia based on morphological and molecular data.

The genus Halosarpheia (Halosphaeriales) was established for marine ascomycetes with obpyriform to sub-globose, coriaceous, brown to black ostiolate ascomata with long necks; hamathecia of catenophyses; thin-walled, unitunicate, persistent asci with thick-walled apices; and ellipsoid, one septate, hyaline ascospores equipped with coiled, threadlike apical appendages that unfurl in water. Emphasis on ascospore appendage morphology has led to the inclusion in the genus of morphologically disparate fungi from a variety of marine and freshwater habitats. To better understand the evolutionary relationships of Halosarpheia species, phylogenetic analyses were conducted on 16 Halosarpheia species, 13 other species of Halosphaeriales and representatives of the Microascales, Hypocreales, Sordariales and Xylariales using 18S and 28S rDNA sequence data. All of the Halosarpheia species occurred on the Halosphaeriales clade. The type species of the genus, H. fibrosa, occurred on a well-supported clade with two morphologically similar species, H. trullifera and H. unicellularis. This clade, which phylogenetically was distant from the clades of other Halosarpheia species, represents the genus Halosarpheia sensu stricto. The other Halosarpheia species were distributed among eight other well-supported clades clearly separated from one another based on molecular data. New generic names are established for six of these clades, one new species is described, and one species is transferred to Aniptodera. A table (Table I) comparing the morphology, habitat, substrate and distribution of the genera of aquatic ascomycetes with coiled, threadlike apical appendages treated in this study is provided, along with a key for their identification.

Tenellic acids A-D: new bioactive diphenyl ether derivatives from the aquatic fungus Dendrospora tenella.

Tenellic acids A-D (1-4) were isolated from cultures of the freshwater fungus Dendrospora tenella. The structures of these new diphenyl ether derivatives were determined primarily by analysis of NMR data. Compounds 1-4 display antimicrobial activity against Gram-positive bacteria.